OPINION

Tracy Glenn Jackson appeals his conviction for robbing a postal employee of money belonging to the United States, in violation of 18 U.S.C.A. § 2114(a) (West 2000). Jackson’s counsel filed a brief asserting that the district court erred in denying his motion for judgment of acquittal. In addition, Jackson filed a motion to file a pro se supplemental brief to assert claims of ineffective assistance of trial counsel.

After a thorough review of the trial transcript, we find that the evidence, when viewed in the light most favorable to the government, was sufficient for a rational trier of fact to have found the essential elements of the crime beyond a reasonable doubt. United States v. Burgos, 94 F.3d 849, 862-63 (4th Cir. 1996) (en banc). We therefore find that the district court did not err in denying the motion for judgment of acquittal.

Jackson claims he was denied effective assistance of counsel because, inter alia, counsel advised him to be clean-shaven for trial, which altered his normal appearance and made him more closely resemble the composite drawings of the robbery suspect, and failed to interview prosecution or defense witnesses. Claims of ineffective assistance generally are not cognizable on direct appeal unless the record conclusively shows that counsel was ineffective. United States v. King, 119 F.3d 290, 295 (4th Cir. 1997). Consequently, although we grant Jackson’s motion to file a pro se supplemental brief, we decline to consider Jackson’s ineffective assistance claims because we find that the record does not conclusively show that counsel was ineffective.

We affirm Jackson’s conviction. We dispense with oral argument because the *219 facts and legal contentions are adequately presented in the materials before the court and argument would not aid the decisional process.

AFFIRMED.